FUEL FILTER

For reliable engine operation and fuel system performance, a clean fuel supply is absolutely essential. That's why replacing the fuel filter is so important. The fuel filter is the fuel system's primary line of defense against dirt, debris and small particles of rust that flake off the inside of the fuel tank. A mesh filter sock on the end of the fuel pickup tube inside the tank helps prevent the big pieces of dirt and rust from entering the fuel line, but it does not keep out smaller particles that can be so troublesome.








FUEL FILTER MEDIA

The filter media may be treated paper, a blend of cellulose and synthetic fibers, glass fibers, sintered bronze, a ceramic material or even a fine nylon mesh. The barrier created by the filter media traps particles and prevents them from reaching the engine. Eventually the filter media becomes clogged with debris, which creates a restriction. If not replaced before it becomes plugged, it can cause major driveability problems (such as hard starting, lack of high speed power and/or stalling).









FUEL FILTER LOCATION



There are two basic types of fuel filters: "inline" filters that are mounted in the fuel line somewhere between the fuel tank and carburetor or fuel rail (EFI), and "internal" filters such as those that fit inside the carburetor fuel inlet on older vehicles.
On most fuel injected vehicles, the fuel filter will be found under the vehicle in the fuel line from the fuel tank to the engine, or on the firewall in the engine compartment. There are also some fuel filters on "returnless" EFI systems (Dodge Ram trucks and other late model Chrysler vehicles) that are located on top of the fuel tank and are part of the fuel pressure regulator assembly. Refer to your owner's manual for the exact location of the filter.





WARNING: Gasoline is highly flammable! To minimize the risk of fire when replacing a fuel filter, make sure there are no sparks or open flames nearby (NO SMOKING!). Also, do not allow any fuel to make contact with a hot exhaust pipe, exhaust manifold or the catalytic converter. And if your using a trouble light with an incandescent bulb, keep it well away from the fuel lines when they are opened or trouble light will take on a whole new meaning for you. A 60 watt bulb in a trouble light gets very hot, and could easily ignite fuel that might drip or spray against the bulb. Trouble lights with cool LED lights or a fluorescent bulb would be a much safer choice for this kind of job.






CAUTION: Fuel injection fuel lines are under pressure. On some vehicles the line pressure may be as high as 85 psi or higher. The fuel pressure inside the line needs to be relieved before the fuel line is disconnected, otherwise fuel will spray everywhere.